Method for improving the efficiency of recoil brake and gun provided with recoil brake

Abstract

The invention relates to a gun provided with recoil brake (14) and a method for improving the efficiency of the same. During the method a portion of the gunpowder gases burnt by means of the oxidant present in the barrel (2) of the gun but still containing inflammable material is introduced as the primary medium from the barrel (2) of the gun into the nozzle (9) of an ejector and the secondary medium is thus pumped in for forming a pre-mixture which is introduced into the combustion chamber of a pulsating reactive drive mechanism (10) acting in a direction opposite to the direction of the shot. This mixture is further burnt by means of the medium containing oxidant present in the drive mechanism (10), the combustion product is led out through the blow pipe (18) and the flow-back taking place during combustion is avoided by means of a valve. The barrel has gas port openings (3) from which the gunpowder gases as primary medium are introduced into the mixed medium transport duct (5) connected to the secondary medium transport duct (4) of the variable operation ejector (8), and in this manner the external oxidant containing medium is pumped in. This mixture from the direction of the nozzle (9) is introduced into the combustion chamber (13) of a pulsating reactive drive mechanism (10), and the flow back is prevented by the ram pressure of the mixture flowing into the combustion chamber (13) through the nozzle (9). The medium present in the combustion chamber (13) is compressed and after the pressure exceeds the pressure in the barrel (2) due to the processes taken place in the combustion chamber (13) and the flow turns back, the combustion product gases as a new primary medium flowing through the nozzle (9) together with the medium transported from the barrel (2) through the mixed medium transport duct (5) and with the medium again transported from the external environment through the secondary medium transport duct (4) is pressed into the afterburner chamber (17) provided on the other side of the variable operation ejector (8) where this mixture is further burnt in the presence of a catalyst reducing the activation energy of the combustible material, then the combustion product is exhausted through the blow pipe (18).

Claims

1. A method for improving efficiency of a recoil brake associated with a gun barrel (2) of a gun, said recoil brake defining a combustion chamber (13) and an afterburner chamber (17) in confined communication with a mixed medium transport duct (5) aligned with the gun barrel (2), which method comprises the steps of: combining in the mixed medium transport duct gunpowder gases from the gun barrel and containing combustibles with an oxidant to produce a mixed medium; compressing the mixed medium into the combustion chamber (13) by means of ram pressure sufficient to initiate combustion and to produce a first combustion product; driving the first combustion product by pressure created in the combustion chamber (13) to the afterburner chamber (17) through a nozzle further compressing the first combustion product; introducing an additional oxidant through the nozzle into the afterburner chamber and producing a second combustion product in the afterburner chamber, and exhausting the second combustion product from the afterburner chamber through a blow pipe (18).

2. The method according to claim 1 wherein an oxidizing catalyst is introduced into the combustion chamber together with the oxidant.

3. The method according to claim 1 wherein an oxidizing catalyst is introduced into the afterburner chamber.

4. The method according to claim 1 wherein an oxidizing catalyst is introduced into the afterburner chamber together with the additional oxidant.

5. A gun comprising: a barrel and a recoil brake attached to the barrel (2); the barrel (2) defining at least one gunpowder gas port opening (3) in vicinity of a muzzle end portion of the barrel (2); the recoil brake defining a combustion chamber (13) and an elongated afterburner chamber (17) which terminates at one end in a nozzle (9) in flow communication with the combustion chamber and terminates in an end opposite said one end in a blowpipe (18) aligned with the gun barrel (2); a medium transport duct (5) positioned between the nozzle (9) and the at least one gas port opening (3) in open flow communication, positioned to receive gunpowder gases mixed with an oxidant, and configured as a Laval nozzle.

Description

(1) A detailed description of a possible advantageous embodiment of the invention will be given with reference to the accompanying drawing.

(2) FIG. 1 shows the longitudinal section of the gun provided with recoil brake according to the invention (only the barrel of the gun is shown).

(3) In the direction of progression of the gunpowder gases the barrel 2 is provided with a barrel gas port opening 3 through which the gunpowder gases are introduced into the mixed medium transport duct 5 of the similarly positioned variable operation ejector 8. The mixed medium transport duct is connected with the external environment through a secondary medium transport duct 4. The mixed medium transport duct 5 is coupled to nozzle 9 through outward opening 6 and is directed towards combustion chamber 13. The secondary medium transport duct 4 and the mixed medium transport duct 5 together with the nozzle 9 form a variable operation ejector 8 which is arranged in the pulsating drive mechanism 10 between its combustion chamber 13 and afterburner chamber 17. Chambers 13 and 17 are connected with nozzle 9. A bolt 7 may be arranged in the mixed medium transport duct 5 of the variable operation ejector 8. In the combustion chamber 13 of the pulsating reactive drive mechanism 10 provided with an afterburner chamber 17 an intake opening 11 having a mechanic valve 12 is provided advantageously opposite to the variable operation ejector 8 and in the afterburner chamber 17 elements containing combustion activating catalyst 16 may be used instead of or in addition to the damming disc 15. Further, the gun provided with recoil brake 14 has a blow pipe 18 arranged following the afterburner chamber through which the combustion product can be led out.

(4) During the method for improving the efficiency of the recoil brake the following steps are taken: The gunpowder gases still containing combustibles are guided from barrel 2 to the mixed medium transport duct 5 of the variable operation ejector 8 through the barrel gas port opening(s). With the gunpowder gas that is with the primary medium flowing rapidly in the mixed medium transport duct 5 by means of the pulse change between the mediums external oxidizing medium i.e. a mixed medium is transported from the secondary medium transport duct 4 through nozzle 9 forming a part of the variable operation ejector 8 to the combustion chamber 13 of the pulsating reactive drive mechanism. As long as the pressure is higher in the barrel 2 than in the combustion chamber 13 the flow proceeds from the barrel gas openings 3 towards the combustion chamber 13 and medium flows even from afterburner chamber 17 towards combustion chamber 13 through nozzle 9. For the time of charging the combustion chamber 13 as long as the energy of the mixed medium flowing from the direction of barrel 2 is higher, this mixed medium is compressed into combustion chamber 13 by means of the ram pressure of the gases and the outflow from combustion chamber 13 is prevented in the same manner. The described charging operation is the first operating state of the variable operation ejector 8. To effectuate the favourably rapid medium flow from the combustion chamber 13 towards the afterburner chamber 17 through the nozzle 9 high pressure must be created in combustion chamber 13. To this charging of the combustion chamber 13 with the mixed medium flowing from the direction of the barrel 2 is not started until the pressure in the combustion chamber 13 of the pulsating reactive drive mechanism 10 provided with an afterburner chamber 17 becomes equal to the pressure of the external environment. In this manner not only a maximum amount of medium containing external oxidant can be introduced by the pulsating reactive drive mechanism 10 provided with the afterburner chamber 17, but as a result of this the mixed medium arriving from the direction of barrel 2 and containing low amount of oxidants combines later, that is, the connection with the medium being in the combustion chamber 13 containing oxidants is established later. In this manner the potential energy of the gunpowder gas is effective for a longer time and a higher amount of mixed medium may be introduced into the combustion chamber 13 from the direction of barrel 2 resulting in a more rapid combustion and higher pressure. Together with the combustion product catalysts or materials containing other oxidants in addition to air may also be introduced into combustion chamber 13. In addition to the combustion product gases (which can be referred to as a new primary medium) flowing from the combustion chamber 13 through nozzle 9 further medium containing external oxidant is pumped and compressed into afterburner chamber 17 by means of the variable operation ejector 8. During this the medium containing the oxidant is pumped through the mixed medium transport duct 5 and the secondary medium transport duct 4 into the gunpowder gas flowing from barrel 2. This is the second operating state of the variable operation ejector 8. In the interest of smooth operation in the afterburner chamber 17 oxidizing catalyst may be used at the damming disc 15 or on the internal superficies of afterburner chamber 17. This is advantageous because the mixture flowing through nozzle 9 towards the direction of afterburner chamber 17 contains little combustible; and contains much neutral combustion product considering the little amount of oxidant. In addition, the pressure in afterburner chamber 17 is not constant. Finally, the combustion product gases are exhausted through blow pipe 18.

(5) An advantage of the invention is that delay of the braking effect is smaller. The efficiency of the recoil brake in relation to its mass is improved.